This project will implement an interdisciplinary program focusing on growth control of normal and malignant cells, and the relationships of mitogens, receptors, oncogenes, and intracellular events. The research projects address three related general questions: how do cells respond to mitogenic factors; what are the roles of cellular oncogene products in these responses; and finally, how are these responses altered in a cancer cell. The program utilizes the expertise of individual investigators within the areas of cell biology, molecular genetics, protein biochemistry, immunology, and molecular pharmacology, and seeks to integrate this expertise in an environment that will accelerate our knowledge about cellular growth and differentiation. In Project 1, we will investigate the possible interactions between growth factor receptors and the viral src protein or its normal cell homologue, c-src. Project 2 outlines an in vitro genetic approach to study the structure and function of v-src and c-src. Experiments proposed in Project 3 (particularly src) are involved in specialized cellular functions, such as secretion of the hormones epinephrine or norepinephrine from adrenal chromaffin cells. In Project 4, experiments which extend previous studies on the response of liver hepatocytes to defined hormones and growth factors will be conducted. (V)